Studies have revealed that the current methods of administering a prescribed amount of aerosolized medication via a continuous, pneumatically operated jet nebulizer, will only provide a small percentage of the drug to be deposited in the lungs of the patient.
In the usual manner, the prescribed medication is instilled into the nebulizer and fitted with a mouthpiece and T connection. The nebulizer is connected to a compressed gas source and flow meter, and the flow rate is adjusted sufficiently to create an aerosol.
The patient is instructed to inhale through the mouthpiece and T connection at an inspiratory flow rate necessary to deliver and to maximize the quantity of the aerosolized medication to the lungs, then passively exhale through the mouthpiece and T connection. This procedure is continued until the nebulizer no longer produces a visible aerosol.
An obvious shortcoming of the above therapeutic modality is that during the intervals when the patient is not inhaling through the mouthpiece, the nebulizer will continuously generate an aerosol during therapy, resulting in a substantial loss of medication.
In the hospital, compressed oxygen is predominately utilized to operate small volume jet nebulizers continuously during the course of therapy. Therefore, there is substantial wastage of oxygen.
The continuous aerosol produced increases the risk of occupational and anybody present within the immediate environment, exposure to medication and infectious agents.
At the present to meet the problems and limitations, a simple finger tip control valve is attached below the nebulizer and inline with the connection tube between the nebulizer and the pneumatic source or compressor.
Normally open, the flow is diverted out of the T valve due to the path of least resistance and the jet nebulizer is deactivated. To activate the nebulizer, the patient by manual means will occlude with the thumb the opening of the T valve to cause flow to be diverted to the jet of the nebulizer to generate an aerosol.
In order to benefit from this procedure, the patient must simultaneously coordinate an inspiratory effort with the manual thumb occlusion of the T control valve. Then promptly release the thumb from the valve at the end of the inspiratory effort, then exhale. The inherent difficulty is the requirement of good hand-lung coordination and patient compliance.
This technique does not assure a decreased wastage of medication and is greatly dependent upon whether the patient effectively releases the thumb from the T control valve at the appropriate intervals, therefore potentially reducing the availability of the aerosolized drug to be deposited in the lungs.
U.S. Pat. No. 4,396,015 issued to Johnson sets forth a MEDICATION CONTROL DEVICE FOR USE IN TREATING LUNGS, having an airway device with a tubular section extending into the first passage for communicating with the negative air pressure sensing port of a positive pressure breathing machine which upon sensing will actuate the nebulizer during the inspiratory phase of each breathing cycle.
This device requires the bulky use of an antiquated breathing machine intended for intermittant positive pressure and therefore inconvenient to operate for routine nebulization.
While the foregoing described devices are representative of the prior art to provide a means of intermittant nebulization, there remains nonetheless a continuing need in the art for an improved and effective intermittant aerosol delivery device.